Method and system for restricting mobility in a wireless local loop

ABSTRACT

A method and system for disabling a mobile unit to handle a call processing function, after being away from its charging unit longer than a predetermined time period, allows a service provider to limit the mobility of the mobile unit with respect to its companion charging unit. Consequently, the service provider may limit the mobility of the mobile unit in a limited area, such as in a wireless local loop.

BACKGROUND

[0001] 1. Field

[0002] The present disclosed embodiments relate generally tocommunications, and more specifically to a wireless local loop.

[0003] 2. Background

[0004] A wireless service provider may operate in a geographical areaunder an exclusive agreement with a local regulator such that otherlocal service providers should not provide similar mobile service totheir customers. Under such arrangements, the local service providersneed to restrict mobility of their wireless customers within a limitedarea. One such environment may be a wireless local loop (WLL).

[0005] To restrict mobility of a mobile, a service provider may limitthe mobility of the mobile's charging unit by, for example, making thecharging unit larger and heavier. However, this solution suffers fromincreased cost and inconvenience to the subscriber. In addition, thesolution may not be effective to restrict the mobility of the mobile, ifthe subscriber may find another similar charging unit while away fromhis or her charging unit. The local operator may require the subscribersto use fixed wireless terminals (FWT) instead of regular mobiles, butFWTs are bulky and more expensive.

[0006] There is therefore a need for a method and system that restrictsthe mobility of mobile units in a WLL.

SUMMARY

[0007] Embodiments disclosed herein address the above stated need. Inone aspect of the invention, a method and system for call processing ina communications system, including a mobile apparatus and a chargingapparatus, allows call processing if the mobile apparatus receives arequest for call processing within a predetermined time period.

[0008] In another aspect of the invention, a method and system for acharging apparatus to interface with a mobile apparatus provides for thecharging apparatus to receive input information from the mobileapparatus, to determine first information from the input information,and to change the first information to second information. The methodand system further provides for the charging apparatus to generateoutput information using the second information, and to send the outputinformation to the mobile apparatus.

[0009] In yet another aspect of the invention, a method and system forenabling a mobile apparatus for call processing causes the mobileapparatus to send input information to a charging apparatus, to receiveoutput information from the charging apparatus in response to the inputinformation, and to enable the mobile apparatus based on the outputinformation received from the charging apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The features, nature, and advantages of the present inventionwill become more apparent from the detailed description set forth belowwhen taken in conjunction with the drawings in which like referencecharacters identify correspondingly throughout and wherein:

[0011]FIG. 1 is a diagram of a wireless communication system thatsupports a number of users;

[0012]FIG. 2 is a simplified block diagram of an embodiment of a basestation and a mobile station;

[0013]FIG. 3 is a representation of a wireless local loop;

[0014]FIG. 4 is a flow chart for a mobile call processing in a wirelesslocal loop; and

[0015]FIG. 5(A) and FIG. 5(B) are flow charts in accordance with oneembodiment of the present invention.

DETAILED DESCRIPTION

[0016] The word “exemplary” is used exclusively herein to mean “servingas an example, instance, or illustration.” Any embodiment describedherein as “exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments.

[0017] A subscriber station, referred to herein as a mobile, maycommunicate with one or more modem pool transceivers (MPTs) referred toherein as base stations. A mobile transmits and receives data packetsthrough one or more modem pool transceivers to a base stationcontroller. Modem pool transceivers and modem pool controllers may beparts of a base station. A base station transports data packets betweenmultiple mobiles. The mobile may be further connected to additionalnetworks, such as a corporate Intranet or the Internet, and maytransport data packets between each mobile and such outside networks. Amobile that has established an active traffic channel connection withone or more modem pool transceivers is called an active mobile, and issaid to be in a traffic state. A mobile that is in the process ofestablishing an active traffic channel connection with one or more modempool transceivers is said to be in a connection setup state. A mobilemay be any data device that communicates through a wireless channel. Amobile may further be any of a number of types of devices including butnot limited to PC card, compact flash, external or internal modem, orwireless phone. The communication link through which the mobile sendsignals to the modem pool transceiver is called a reverse link. Thecommunication link through which a modem pool transceiver sends signalsto an access terminal is called a forward link.

[0018]FIG. 1 is a diagram of a wireless communication system 100 thatsupports a number of users and is capable of implementing variousaspects of the invention. System 100 provides communication for a numberof cells, with each cell being serviced by a corresponding base station104. The base stations are also commonly referred to as base transceiversystems (BTSs). Various remote terminals 106 are dispersed throughoutthe system. Each remote terminal 106 may communicate with one or morebase stations 104 on the forward and reverse links at any particularmoment, depending on whether or not the remote terminal is active andwhether or not it is in soft handoff. The forward link refers totransmission from base station 104 to remote terminal 106, and thereverse link refers to transmission from remote terminal 106 to basestation 104. As shown in FIG. 1, base station 104 a communicates withremote terminals 106 a, 106 b, 106 c, and 106 d, and base station 104 bcommunicates with remote terminals 106 d, 106 e, and 106 f. Remoteterminal 106 d is in soft handoff and concurrently communicates withbase stations 104 a and 104 b.

[0019] In system 100, a base station controller (BSC) 102 couples tobase stations 104 and may further couple to a public switched telephonenetwork (PSTN). The coupling to the PSTN may be achieved via a mobileswitching center (MSC), which is not shown in FIG. 1 for simplicity. ABSC may also couple into a packet network, which is typically achievedvia a packet data serving node (PDSN) that is also not shown in FIG. 1.BSC 102 provides coordination and control for the base stations coupledto it. BSC 102 further controls the routing of telephone calls amongremote terminals 106, and between remote terminals 106 and users coupledto the PSTN (e.g., conventional telephones) and to the packet network,via base stations 104.

[0020] System 100 may be designed to support one or more wirelessstandards. Such standards may include the CDMA standards such as (1) the“TIA/EIA-95-B Mobile Station-Base Station Compatibility Standard forDual-Mode Wideband Spread Spectrum Cellular System” (the IS-95standard); (2) the “TIA/EIA-98-D Recommended Minimum Standard forDual-Mode Wideband Spread Spectrum Cellular Mobile Station” (the IS-98standard); (3) the documents offered by a consortium named “3rdGeneration Partnership Project” (3GPP) and embodied in a set ofdocuments including Document Nos. 3G TS 25.211, 3G TS 25.212, 3G TS25.213, and 3G TS 25.214 (the W-CDMA standard); and (4) the documentsoffered by a consortium named “3rd Generation Partnership Project 2”(3GPP2) and embodied in a set of documents including Document Nos.C.S0002-A, C.S0005-A, C.S0010-A, C.S0011-A. C.S0024, and C.S0026 (thecdma2000 standard). In the case of the 3GPP and 3GPP2 documents, theseare converted by standards bodies worldwide (e.g., TIA, ETSI, ARIB, TTA,and CWTS) into regional standards and have been converted intointernational standards by the International Telecommunications Union(ITU). These standards are incorporated herein by reference.

[0021]FIG. 2 is a simplified block diagram of an embodiment of basestation 204 and remote terminal 206, which are capable of implementingvarious aspects of the invention. For a particular communication, voicedata, packet data, and/or messages may be exchanged between base station204 and remote terminal 206, via an air interface 208. Various types ofmessages may be transmitted, such as messages used to establish acommunication session between the base station and remote terminal andmessages used to control a data transmission (e.g., power control, datarate information, acknowledgment, and so on). Some of these messagetypes are described in further detail below.

[0022] For the reverse link, at remote terminal 206, voice and/or packetdata (e.g., from a data source 210) and messages (e.g., from acontroller 230) are provided to a transmit (TX) data processor 212,which formats and encodes the data and messages with one or more codingschemes to generate coded data. Each coding scheme may include anycombination of cyclic redundancy check (CRC), convolutional, turbo,block, and other coding, or no coding at all. The voice data, packetdata, and messages may be coded using different schemes, and differenttypes of messages may be coded differently.

[0023] The coded data is then provided to a modulator (MOD) 214 andfurther processed (e.g., covered, spread with short PN sequences, andscrambled with a long PN sequence assigned to the user terminal). Themodulated data is then provided to a transmitter unit (TMTR) 216 andconditioned (e.g., converted to one or more analog signals, amplified,filtered, and quadrature modulated) to generate a reverse link signal.The reverse link signal is routed through a duplexer (D) 218 andtransmitted via an antenna 220 to base station 204.

[0024] At base station 204, the reverse link signal is received by anantenna 250, routed through a duplexer 252, and provided to a receiverunit (RCVR) 254. Receiver unit 254 conditions (e.g., filters, amplifies,down converts, and digitizes) the received signal and provides samples.A demodulator (DEMOD) 256 receives and processes (e.g., despreads,decovers, and pilot demodulates) the samples to provide recoveredsymbols. Demodulator 256 may implement a rake receiver that processesmultiple instances of the received signal and generates combinedsymbols. A receive (RX) data processor 258 then decodes the symbols torecover the data and messages transmitted on the reverse link. Therecovered voice/packet data is provided to a data sink 260 and therecovered messages may be provided to a controller 270. The processingby demodulator 256 and RX data processor 258 are complementary to thatperformed at remote terminal 206. Demodulator 256 and RX data processor258 may further be operated to process multiple transmissions receivedvia multiple channels, e.g., a reverse fundamental channel (R-FCH) and areverse supplemental channel (R-SCH). Also, transmissions may besimultaneously from multiple remote terminals, each of which may betransmitting on a reverse fundamental channel, a reverse supplementalchannel, or both.

[0025] On the forward link, at base station 204, voice and/or packetdata (e.g., from a data source 262) and messages (e.g., from controller270) are processed (e.g., formatted and encoded) by a transmit (TX) dataprocessor 264, further processed (e.g., covered and spread) by amodulator (MOD) 266, and conditioned (e.g., converted to analog signals,amplified, filtered, and quadrature modulated) by a transmitter unit(TMTR) 268 to generate a forward link signal. The forward link signal isrouted through duplexer 252 and transmitted via antenna 250 to remoteterminal 206.

[0026] At remote terminal 206, the forward link signal is received byantenna 220, routed through duplexer 218, and provided to a receiverunit 222. Receiver unit 222 conditions (e.g., down converts, filters,amplifies, quadrature modulates, and digitizes) the received signal andprovides samples. The samples are processed (e.g., despreaded,decovered, and pilot demodulated) by a demodulator 224 to providesymbols, and the symbols are further processed (e.g., decoded andchecked) by a receive data processor 226 to recover the data andmessages transmitted on the forward link. The recovered data is providedto a data sink 228, and the recovered messages may be provided tocontroller 230.

[0027] A wireless communications system, as described in FIG. 2 for anexemplary embodiment of the invention, may be utilized in a wirelesslocal loop (WLL) as shown in FIG. 3, for example. FIG. 3 shows arepresentation of a communications system infrastructure where atraditional wire local loop (LL) 306 may be replaced with a wirelesslocal loop (WLL) 310. The traditional LL 306 connects subscribers 308A,308B to the distribution point 304B through wire cables, whereas the WLL310 connects subscribers 312A, 312B to the distribution point 304Bthrough wireless communication. In one embodiment, the base station 204(FIG. 2) may be positioned at a distribution point 304B, such that themobile station 206 (FIG. 2) may provide wireless communication serviceto subscribers 312A and 312B in a limited range, such as a sector.

[0028] To restrict mobility for the mobiles operating in the WLL 310,according to one embodiment of the present invention, a WLL timer may beprovided for each mobile such that the mobile may not be able to respondto a request for call processing if the request is received by themobile after a predetermined time period. The WLL timer may be asoftware timer inside the mobile. The request for call processing mayinclude a request to initiate a call or a request to receive an incomingcall.

[0029]FIG. 4 shows a flow chart 400 for restricting mobile callprocessing according to one embodiment. A mobile may be in an idle state402, when it may receive a request for call processing, in step 404. Instep 406, the mobile may check a WLL timer to determine if apredetermined time period has expired. If the predetermined time periodhas expired, the mobile may be disabled to handle the requested callprocessing, and may return to idle state 402. If, however, thepredetermined time period has not expired, the mobile may be enabled, instep 408, to handle the requested call processing.

[0030] One embodiment for enabling a mobile for call processing will bedescribed in reference to FIG. 5(A) and FIG. 5(B). A mobile may gothrough an enabling process while the mobile is in idle state. In oneembodiment, the enabling process may be periodic. In the idle state, amobile may periodically monitor a paging or control channel for overheadmessages and parameters, which may also include control signals and datafor enabling the mobile for call processing, according to one embodimentof the invention. In one embodiment, a mobile may go through theenabling process when the mobile is positioned on a dedicated chargingunit that is dedicated to the mobile. A charging unit may include amicrocontroller for implementing the mobile enabling process, devicesfor performing mobile charging, and input/output devices forcommunicating with the mobile. A mobile may also include necessarydevices for information processing and input/output operations.

[0031] The mobile enabling process may be carried out through anencryption process between a mobile and a charging unit, as will bedescribed below. The encryption process may be implemented by exchangingsecure random codes between the mobile and the charging unit. Afterdetermining that the mobile is legitimately communicating with itsdedicated charging unit, the mobile may be enabled for call processingfor only a predetermined time period, or alternatively for apredetermined distance form the charging unit, which restricts themobility of the mobile if taken away from its dedicated charging unit.

[0032] In step 502, a mobile may generate a first random number or code,N, based on some predetermined criteria. In step 504, the mobile mayencrypt the first code N with a common code, P, which is commonly knownby the mobile and its companion charging unit. The common code P may beprogrammed inside both the mobile and the dedicated charging unit, whichmay be dedicated to each other during the provisioning process by theservice provider. The programming process may be carried out through thedata ports provided for the mobile and its charging unit. The commoncode P may be programmed inside memory devices located inside the mobileand its dedicated charging unit. For security purposes, the programmingof the code P may be restricted to only when the target memory devicesare blank, such that such memory devices in the mobile and the chargingunit are one-time programmable. Such memory devices may be flash memorydevices. In another embodiment, the mobile may encrypt the first code Nby using a private code and a public code, an encryption technique thatis well known in the art.

[0033] In step 506, the mobile may also encrypt a predeterminedvariation of the first code N to generate a second code, e.g., N+1,using the same common code P. In step 508, the mobile attempts to sendthe encrypted first code N to its dedicated charging unit. In step 510,the mobile determines whether the mobile is positioned on its dedicatedcharging unit. If the mobile is positioned on its companion chargingunit, the mobile sends, and the charging unit receives, the encryptedfirst code N, in step 512. If, however, the mobile is not positioned onits companion charging unit, the mobile may not be enabled for callprocessing, and may transition to idle state 502, where the mobile maywait for the next enabling cycle.

[0034] In step 514, the charging unit, having received an encryptedfirst code N from its companion mobile and knowing the common code P,decrypts the first code N. Similar to step 506, the charging unit, instep 516, generates the same predetermined variation of the first code Nto generate a second code, e.g., N+1, using the same common code P. Instep 518, the charging unit sends the encrypted second code, N+1, to itscompanion mobile. In step 520, the mobile receives and decrypts, usingthe common code P, the output information it has received from itscompanion charging unit. In step 522, the mobile compares the decryptedoutput signal received from its dedicated charging unit with the storedsecond code N+1 that the mobile had generated in step 506, as discussedabove. If these two codes match, it is verified that the mobile isactually positioned on its dedicated charging unit, and thus the mobileis enabled for call processing. In one embodiment, the mobile may beenabled for a predetermined period of time, for example by resetting aWLL timer in the mobile to a predetermined value, in step 526.Alternatively, a down counter may be used. If, however, the result ofthe comparison in step 5224 is negative, which indicates that the mobilemay not be positioned on its companion charging unit, the mobile is notenabled and may transition to the idle state 502, where the mobile maywait for the next enabling cycle.

[0035] According to one embodiment of the invention, the mobile may beenabled for call processing if the mobile is located within apredetermined distance from its dedicated charging unit. In thisembodiment, the mobile may communicate to its dedicated charging unitthrough limited-range wireless communications means, which allows anencryption method, such as one described above, to be performed whilethe mobile is not necessarily positioned on its dedicated charging unit.One such limited wireless communications device may be Bluetooth™wireless technology, for example.

[0036] By disabling the mobile to handle a call processing functionafter being away from its dedicated charging station for a predeterminedtime period, the service provider may limit the mobility of its mobileswith respect to their companion charging units. The service provider mayalso limit the mobility of the charging units by, for example, makingthem larger and heavier. Consequently, the service provider may limitthe mobility of the mobiles in a limited area, such as in a wirelesslocal loop.

[0037] Advantageously, no hardware modifications are required for amobile to operate in a WLL, as described above. In addition, after a“mobile license” is granted to a subscriber, the mobile may be easilyreprogrammed to lift its programmed mobility restriction.

[0038] Those of skill in the art would understand that information andsignals may be represented using any of a variety of differenttechnologies and techniques. For example, data, instructions, commands,information, signals, bits, symbols, and chips that may be referencedthroughout the above description may be represented by voltages,currents, electromagnetic waves, magnetic fields or particles, opticalfields or particles, or any combination thereof.

[0039] Those of skill would further appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the embodiments disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present invention.

[0040] The various illustrative logical blocks, modules, and circuitsdescribed in connection with the embodiments disclosed herein may beimplemented or performed with a general purpose processor, a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

[0041] The steps of a method or algorithm described in connection withthe embodiments disclosed herein may be embodied directly in hardware,in a software module executed by a processor, or in a combination of thetwo. A software module may reside in RAM memory, flash memory, ROMmemory, EPROM memory, EEPROM memory, registers, hard disk, a removabledisk, a CD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such the processorcan read information from, and write information to, the storage medium.In the alternative, the storage medium may be integral to the processor.The processor and the storage medium may reside in an ASIC. The ASIC mayreside in a mobile. In the alternative, the processor and the storagemedium may reside as discrete components in a mobile unit.

[0042] The previous description of the disclosed embodiments is providedto enable any person skilled in the art to make or use the presentinvention. Various modifications to these embodiments will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other embodiments without departing from thespirit or scope of the invention. Thus, the present invention is notintended to be limited to the embodiments shown herein but is to beaccorded the widest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A mobile apparatus comprising: means forreceiving a request for call processing; and means for allowing the callprocessing if the mobile apparatus receives the request within apredetermined time period.
 2. The mobile apparatus of claim 1, whereinthe mobile apparatus is dedicated to a charging apparatus.
 3. The mobileapparatus of claim 2, wherein the mobile apparatus is dedicated to thecharging apparatus through a common code programmed in each.
 4. Themobile apparatus of claim 3, wherein a timer measures the predeterminedtime period.
 5. The mobile apparatus of claim 4, wherein the timer isset while the mobile apparatus is positioned on the charging apparatus.6. The mobile apparatus of claim 5, wherein the timer is within themobile apparatus.
 7. The mobile apparatus of claim 6, wherein the timeris a software timer.
 8. The mobile apparatus of claim 1, wherein themobile apparatus operates in a wireless local loop.
 9. A chargingapparatus for restricting mobility of a mobile apparatus, comprising:means for receiving input information from the mobile apparatus; meansfor determining first information from the input information; means forchanging the first information to second information; means forgenerating output information using the second information; and meansfor sending the output information to the mobile apparatus.
 10. Thecharging apparatus of claim 9, wherein the mobile apparatus is dedicatedto the charging apparatus.
 11. The charging apparatus of claim 10,wherein the means for determining further includes means for decryptingthe input information based on a common code known to the mobileapparatus and the charging apparatus.
 12. The charging apparatus ofclaim 11, wherein the second information is known by the mobileapparatus and the changing apparatus.
 13. The charging apparatus ofclaim 12, wherein the means for generating further includes means forencrypting the second information based on the common code known to themobile apparatus and the charging apparatus.
 14. The charging apparatusof claim 9, wherein the charging apparatus operates in a wireless localloop.
 15. A method for call processing in a communications systemincluding a mobile apparatus and a charging apparatus, the methodcomprising: receiving a request for a call processing by the mobileapparatus; and allowing the call processing if the mobile apparatusreceives the request within a predetermined time period.
 16. The methodof claim 15, further including measuring the predetermined time periodby a timer.
 17. The method of claim 16, further including setting thetimer while the mobile apparatus is positioned on the charging apparatusthat is dedicated to the mobile apparatus.
 18. The method of claim 15,further operating in a wireless local loop.
 19. A method for a chargingapparatus to interface with a mobile apparatus, the method comprising:receiving input information from the mobile apparatus; determining firstinformation from the input information; changing the first informationto second information; generating output information using the secondinformation; and sending the output information to the mobile apparatus.20. The method of claim 19, further operating while the mobile apparatusis positioned on the charging apparatus that is dedicated to the mobileapparatus.
 21. The method of claim 20, wherein the determining furtherincludes decrypting the input information based on a common code knownto the mobile apparatus and the charging apparatus.
 22. The method ofclaim 21, wherein the second information is known by the mobileapparatus and the changing apparatus.
 23. The method of claim 22,wherein the generating further includes encrypting the secondinformation based on the common code known to the mobile apparatus andthe charging apparatus.
 24. The method of claim 23, further operating ina wireless local loop.
 25. A method for enabling a mobile apparatus forcall processing, the method comprising: sending input information fromthe mobile apparatus to a charging apparatus; receiving outputinformation from the charging apparatus; and enabling the mobileapparatus based on the output information received from the chargingapparatus.
 26. The method of claim 25, wherein the sending furtherincludes encrypting first information based on a common code known tothe mobile apparatus and the charging apparatus.
 27. The method of claim26, wherein the enabling further includes determining second informationfrom said output information based on the common code known to themobile apparatus and the charging apparatus.
 28. The method of claim 27,wherein the enabling further includes enabling the mobile apparatus ifthe second information matches a predetermined variation of the firstinformation.
 29. The method of claim 25, wherein the enabling furtherincludes enabling the mobile apparatus for a predetermined period oftime.
 30. The method of claim 25, wherein the enabling further includesenabling the mobile apparatus while the mobile apparatus is positionedon the charging apparatus that is dedicated to the mobile apparatus. 31.The method of claim 25, wherein the enabling further includes enablingthe mobile apparatus while the mobile apparatus is located within apredetermined distance from the charging apparatus that is dedicated tothe mobile apparatus.
 32. The method of claim 25, wherein the enablingfurther includes enabling the mobile apparatus for a predetermineddistance from the charging apparatus that is dedicated to the mobileapparatus.
 33. A computer readable medium embodying a method for acharging apparatus to interface with a mobile apparatus, the methodcomprising: receiving input information from the mobile apparatus;determining first information from the input information; changing thefirst information to second information; generating output informationusing the second information; and sending the output information to themobile apparatus.
 34. A computer readable medium embodying a method forenabling a mobile apparatus for call processing, the method comprising:sending input information from the mobile apparatus to a chargingapparatus; receiving output information from the charging apparatus; andenabling the mobile apparatus based on the output information receivedfrom the charging apparatus.